Merge pull request #664 from louis-e/single-bbox

Fix world lock held during map preview generation

src/data_processing.rs

@@ -275,6 +275,8 @@ pub fn generate_world_with_options(
     // Save world
     editor.save();
 
+    emit_gui_progress_update(99.0, "Finalizing world...");
+
     // Update player spawn Y coordinate based on terrain height after generation
     #[cfg(feature = "gui")]
     if world_format == WorldFormat::JavaAnvil {
@@ -303,8 +305,6 @@ pub fn generate_world_with_options(
         }
     }
 
-    emit_gui_progress_update(99.0, "Finalizing world...");
-
     // For Bedrock format, emit event to open the mcworld file
     if world_format == WorldFormat::BedrockMcWorld {
         if let Some(path_str) = output_path.to_str() {
@@ -312,41 +312,72 @@ pub fn generate_world_with_options(
         }
     }
 
-    // Generate top-down map preview silently in background after completion (Java only)
-    // Skip map preview for very large areas to avoid memory issues
-    const MAX_MAP_PREVIEW_AREA: i64 = 6400 * 6900;
-    let world_width = (xzbbox.max_x() - xzbbox.min_x()) as i64;
-    let world_height = (xzbbox.max_z() - xzbbox.min_z()) as i64;
-    let world_area = world_width * world_height;
-
-    if world_format == WorldFormat::JavaAnvil && world_area <= MAX_MAP_PREVIEW_AREA {
-        let world_path = args.path.clone();
-        let bounds = (
-            xzbbox.min_x(),
-            xzbbox.max_x(),
-            xzbbox.min_z(),
-            xzbbox.max_z(),
-        );
-        std::thread::spawn(move || {
-            // Use catch_unwind to prevent any panic from affecting the application
-            let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
-                map_renderer::render_world_map(&world_path, bounds.0, bounds.1, bounds.2, bounds.3)
-            }));
-
-            match result {
-                Ok(Ok(_path)) => {
-                    // Notify the GUI that the map preview is ready
-                    emit_map_preview_ready();
-                }
-                Ok(Err(e)) => {
-                    eprintln!("Warning: Failed to generate map preview: {}", e);
-                }
-                Err(_) => {
-                    eprintln!("Warning: Map preview generation panicked unexpectedly");
-                }
-            }
-        });
-    }
-
     Ok(output_path)
 }
+
+/// Information needed to generate a map preview after world generation is complete
+#[derive(Clone)]
+pub struct MapPreviewInfo {
+    pub world_path: PathBuf,
+    pub min_x: i32,
+    pub max_x: i32,
+    pub min_z: i32,
+    pub max_z: i32,
+    pub world_area: i64,
+}
+
+impl MapPreviewInfo {
+    /// Create MapPreviewInfo from world bounds
+    pub fn new(world_path: PathBuf, xzbbox: &XZBBox) -> Self {
+        let world_width = (xzbbox.max_x() - xzbbox.min_x()) as i64;
+        let world_height = (xzbbox.max_z() - xzbbox.min_z()) as i64;
+        Self {
+            world_path,
+            min_x: xzbbox.min_x(),
+            max_x: xzbbox.max_x(),
+            min_z: xzbbox.min_z(),
+            max_z: xzbbox.max_z(),
+            world_area: world_width * world_height,
+        }
+    }
+}
+
+/// Maximum area for which map preview generation is allowed (to avoid memory issues)
+pub const MAX_MAP_PREVIEW_AREA: i64 = 6400 * 6900;
+
+/// Start map preview generation in a background thread.
+/// This should be called AFTER the world generation is complete, the session lock is released,
+/// and the GUI has been notified of 100% completion.
+///
+/// For Java worlds only, and only if the world area is within limits.
+pub fn start_map_preview_generation(info: MapPreviewInfo) {
+    if info.world_area > MAX_MAP_PREVIEW_AREA {
+        return;
+    }
+
+    std::thread::spawn(move || {
+        // Use catch_unwind to prevent any panic from affecting the application
+        let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
+            map_renderer::render_world_map(
+                &info.world_path,
+                info.min_x,
+                info.max_x,
+                info.min_z,
+                info.max_z,
+            )
+        }));
+
+        match result {
+            Ok(Ok(_path)) => {
+                // Notify the GUI that the map preview is ready
+                emit_map_preview_ready();
+            }
+            Ok(Err(e)) => {
+                eprintln!("Warning: Failed to generate map preview: {}", e);
+            }
+            Err(_) => {
+                eprintln!("Warning: Map preview generation panicked unexpectedly");
+            }
+        }
+    });
+}

src/gui.rs

@@ -963,17 +963,27 @@ fn gui_start_generation(
 
                 let _ = data_processing::generate_world_with_options(
                     parsed_elements,
-                    xzbbox,
+                    xzbbox.clone(),
                     args.bbox,
                     ground,
                     &args,
-                    generation_options,
+                    generation_options.clone(),
                 );
                 // Explicitly release session lock before showing Done message
                 // so Minecraft can open the world immediately
                 drop(_session_lock);
                 emit_gui_progress_update(100.0, "Done! World generation completed.");
                 println!("{}", "Done! World generation completed.".green().bold());
+
+                // Start map preview generation silently in background (Java only)
+                if world_format == WorldFormat::JavaAnvil {
+                    let preview_info = data_processing::MapPreviewInfo::new(
+                        generation_options.path.clone(),
+                        &xzbbox,
+                    );
+                    data_processing::start_map_preview_generation(preview_info);
+                }
+
                 return Ok(());
             }
 
@@ -1006,7 +1016,7 @@ fn gui_start_generation(
 
                     let _ = data_processing::generate_world_with_options(
                         parsed_elements,
-                        xzbbox,
+                        xzbbox.clone(),
                         args.bbox,
                         ground,
                         &args,
@@ -1017,6 +1027,16 @@ fn gui_start_generation(
                     drop(_session_lock);
                     emit_gui_progress_update(100.0, "Done! World generation completed.");
                     println!("{}", "Done! World generation completed.".green().bold());
+
+                    // Start map preview generation silently in background (Java only)
+                    if world_format == WorldFormat::JavaAnvil {
+                        let preview_info = data_processing::MapPreviewInfo::new(
+                            generation_options.path.clone(),
+                            &xzbbox,
+                        );
+                        data_processing::start_map_preview_generation(preview_info);
+                    }
+
                     Ok(())
                 }
                 Err(e) => {

src/gui/js/bbox.js

@@ -899,6 +899,15 @@ $(document).ready(function () {
             });
         }
 
+        // If it's a rectangle, remove any existing rectangles first
+        if (e.layerType === 'rectangle') {
+            drawnItems.eachLayer(function(layer) {
+                if (layer instanceof L.Rectangle) {
+                    drawnItems.removeLayer(layer);
+                }
+            });
+        }
+
         // Check if it's a rectangle and set proper styles before adding it to the layer
         if (e.layerType === 'rectangle') {
             e.layer.setStyle({

tauri.conf.json

@@ -16,7 +16,7 @@
         "minWidth": 1000,
         "minHeight": 650,
         "resizable": true,
-        "transparent": true,
+        "transparent": false,
         "center": true,
         "theme": "Dark",
         "additionalBrowserArgs": "--disable-features=VizDisplayCompositor"